The goals of this research are to understand the molecular basis of the interactions of several neurotoxic polypeptides from sea anemones by first elucidating their-dimensional structure in solution by state-of- the-art NMR and related techniques (ESR spin labeling, CIDNP) The combined results of these approaches allow us to define both the average and dynamic structures of, e.g., tenebrosins-A, -B, and -C from the Australian sea anemone. The experimental approaches will involve collaborative molecular biological approaches as well, allowing specific isotopic labeling for higher order (3-D, 4-D) NMR studies. Following a 6-month visit, two annual 3-month visits are planned with ESR an CIDNP studies at Ohio State in the interim.